1. Field of the Invention
The present invention relates to a driving method for a plasma display panel (PDP), and particularly, to a driving method for a plasma display panel capable of improving luminous efficiency thereof and prolonging a life span thereof.
2. Description of the Conventional Art
A general plasma display panel (PDP) is typically a display in which ultraviolet rays generated by the discharge of inactive gas, which is obtained by mixing helium (He) and xenon (Xe) or neon (Ne) and xenon (Xe), excite phosphors to realize images including texts or graphics. The plasma display panel is characterized by facilitating its scale-up, and providing a superior image quality and a fast response speed. Also, since the plasma display panel is possible to be thin, it attracts attention as a wall-mounted display together with a field emission display, a thin film transistor liquid crystal display, or the like.
A monochromatic plasma display panel device directly uses visible rays emitted from a discharge gas in order to display images. There may, for instance, be a PDP using orange rays given out from a neon (Ne) gas. In case that full color is required to be displayed, the PDP uses visible rays generated by allowing ultraviolet rays generated from the discharge gas such as krypton (Kr) or Xenon (Xe) to excite phosphors for red (R), green (G), and blue (B).
The plasma display panel is a display device using a discharge of gas so as to be also called as a gas discharge display device.
The plasma display panel is classified depending on types of the discharge into a DC type, an AC type, or a hybrid type. The DC type has characteristics that an electrode used for applying a voltage supplied from the external to form the plasma is directly exposed to the plasma and thus a conduction current directly flows through the electrode. The AC type has characteristics that the electrode is covered with a dielectric not to be directly exposed to the plasma and thus a displacement current flows through the electrode.
Also, the plasma display panel may also be classified depending on how the electrode is arranged into an opposed discharge type, a surface discharge type, a barrier discharge type, or the like. In particular, as an example of the surface discharge type, a three-electrode surface discharge type alternating current plasma display panel is comprised of: sustain electrodes located in parallel at a lower portion of a same upper glass substrate; an upper substrate including a dielectric covering the sustain electrodes; and a lower substrate placed at an upper portion of the lower glass substrate, having a certain interval by a barrier structure, and including an address electrode which is formed to be intersected with the sustain electrodes in its vertical direction. The discharge gas is sealed in a space between the upper and lower substrates and the barrier structure is sealed. In the three-electrode surface discharge type alternating current plasma display panel, wall charges are accumulated on the surface of the dielectric which covers the sustain electrodes during the discharge for the display panel, and displays data using memory characteristics by the accumulated wall charge.
Hereinafter, with reference to FIGS. 1 through 3, it will be explained a sustain discharge driving method by illustrating the general three-electrode surface discharge type alternating current plasma display panel.
FIG. 1 briefly shows discharge cells in the general three-electrode surface discharge type alternating current plasma display panel.
Referring to FIG. 1, a single discharge cell of the general three-electrode surface discharge type alternating current plasma display panel (hereinafter, the plasma display panel) is comprised of: two sustain electrodes (Y electrode and Z electrode) located on the same surface, address electrode (X electrode) vertically intersecting with the sustain electrodes, and phosphor placed between the sustain electrodes and the address electrode.
FIG. 2 shows operational waveforms applied to each electrode while sustaining a discharge for the general plasma display panel based on the conventional art.
FIG. 3 shows charges formed on each electrode while sustaining the discharge for the general plasma display panel based on the conventional art.
As shown in FIG. 2, in the conventional sustain discharge driving method for the general plasma display panel, the sustain discharge is performed by alternately applying a first predetermined positive voltage pulse Vsy and a second predetermined positive voltage pulse Vsz to the discharge sustain electrodes (Y sustain electrode and Z sustain electrode). In response to this, as shown in FIG. 3, positive charges are always accumulated in the address electrode (X electrode) without regard to the first and second predetermined positive voltage pulses Vsy and Vsz applied to the Y sustain electrode and the Z sustain electrode while sustaining the discharge for the plasma display panel based on the conventional art.
However, when sustaining the discharge, if the positive charges are accumulated on the address electrodes (X electrodes), particles of the electrodes come off by an impact between phosphors of the discharge cell and positive ions cling to the inside of the wall of the discharge cell, which results in degrading luminous efficiency of the plasma display panel and enhancing aging of the phosphors. As a result, the plasma display panel disadvantageously has had a shorter life span.